Lamp.



W. C. M. PETTINGILL,

LAMP.

APPLIOATION FILED MAY 19, 1913.

Patented Aug. 25, 1914.

u 0 MY 7 m r R5 0 r MQMM AY @WaA WALTER CECIL MANTBY PETTINGILL, OF BIRMINGHAM, ENG-LAND.

LAMP.

Specification of Letters Patent.

Patented Aug. 25, 1914.

Application filed May in. ms. Serial No. 768,548.

Tor/ll whom t t-may concern I lie it known that I, VAT/FER Cami. Maxrnr PETTINcILL, subject of the King of Great Britain, residing at etT Francis road, Edgbaston Birmingham, in the county of Warwick, England, have invented a new and useful Lamp; and I do hereby declare the following to be a full, clear, and exact description of the same. V

This invention comprises improvements in and relating toanti-glare devices for lamps fitted with reflectors, or with lenses, or with reflectors and lenses and it has for its object an antiglare device or arrangement which will be simplein construction and which willnot' diminish the useiul light emitted by the lamp.

I The invention is very useful in connection with the lamps used on motor vehicles.

According to this invention, those. rays from the source oflight which normally give rise to upper reflections are intercepted-or obviated and thereby prevented from reaching the reflecting medium or media.

Inone way of carrying out this invention, Iso'position or group a screen or screens in relation to the source of light as to intercept rays which give rise to undesirable upper reflections and thereby prevent said rays from reaching the reflecting medium or media. In another way of carrying out this invention, the source of light is so shaped and positioned inthe focal plane of the .lamp as to emit rays which when reflected from the refleeting medium or media constitute an" illumination lacking the undesirable upper rays. In both these methods, the light projccted by the lamp has a well-defined upper edge and the amount of restriction imposed on the projected light can be varied as re quired, the volume of useful light below the umbra thus created being unimpaired.

My invention can be carried into practice in various ways, some examples being illustrated on the accompanying drawing on which:

Figure 1 is a sectional elevation of a lamp fitted with a rear reflector showing my invention applied thereto. Fig. 2 is a sectional elevation of a lamp fitted with a front lens with my invention applied thereto. Fig. 3 is an elevation at right angles to Fig. 1 showing the screen. Fig. t is a fragmentary vieyw showingmeans for operating the screen. I Fig; 5 is another fragmentary view less sharply defined;

showing a modification of the screen operating means. Fig. (3 is a sectional elevation of a lamp fitted with a parabolic reflector showing the application of the invention to that type of lamp.

In the lamp shown in Fig. 1, the flame 1 or other source of illumination is arranged slightly in front of the true focus 2 of the refiector 3 of the concave type ofthe lamp i, and in the focal plane close behind the source of light 1 is located a small screen t made of metal or other suitable material. Preferably thescreeri is of semicircular shape with the straight edge 6 uppermost and is preferably disposed so that such straight edge 6 is slightly below the horizontal axis of the reflector 3, the dimensions of the, screen being such as will stop the passage of rays from-the light source below the said straight edge 6. By this means, the upper rays of the cone of light normally projected by the lamp are out OK in a sharply definedmanner without appreciably aflectin the strength of the other rays, this being no to the fact that the area of the screen is small in comparison with that of the reflector. The screen may be shaped to-cut off an desired rays of the cone of light and to cave any others, the fact being kept in view that it' the lamp be directed to illuminate a distant plane. an inverted image of the screen in shadow will be formed thereon. as the screen in thelfocal plane of the reflector.

It is not essential that the light source and the screen be arranged as describeches by locating them a little in front of or to the rear of the positionsspecifi'ed, the cutting otl of the .rays merely'becomes little Instead of fixing the screen 5 to the burner 7 by a horizontal perforated eye 8 as in Fig. 1, it may be fixed to the body of the lamp, or as shown in Fig: 4: may be mounted on a lever arm 9 pivoted to a bracket 1O fixed. to the lamp body. In this case, the screen 5 is capable of being swung or displaced to a position in which it does not interfere with the passage of light to the reflector to any material extent, thereby allowing the driver of the vehicle to cut oil? the rays to any desired extent.

In Fig. 4, a quadrant 11 is attached to the pivbt'ed lever 9 to accommodate the. inextensible inner member 12 of a flexible cable the outer incompressible member 14 of which is enchorediitz at stop 15. The other end of the member 12 is connected to a lever under the control of the driver.

In Fig. the pivoted lever 9 has an outwerdly ending. part 16 furnished with 3, aloell 1'4, spring; and spring box 19, said hull forming a detent, to hold the pivoted lever 9 and attached screen 5 in either the v operative position or the inoperative posir. iuedrunt 530 with depressions 21 is provided for engagement by the ball 17.

llhe application of the invention to a lamp of the t titted with e lens in front of the source 0. lisht is illustrated in Fig. .--.2, in which n n 5 is arranged just in front'ol the ,e of light 1 to cut oii the upperrey-s 0:: the cone of light from the front lens 22. As t-hisscreen is similar to that shown in Fig. 8, it is not further described.

in those lamps in which a parabolic reflector is used, see Fig. 6, the rear rays and alse those which normally strike sidewise from the lower part of the light are screened by an annular s nient 28 with straight upper edge 24;, win n subtends a, suitable angle so to surround the lower part of the source oi light .i, the top straight edge 24 below the axis of the lamp.

mouse? Having thus described my invention whet I claim 15: I

1. In a lamp, the combination of a source of light, means for increasing the intensity of the projected beam, and a screen having a, substantially -horizontal upper edge and situated in the focal plane of the intensifying means, said screen lying" Wholly below the optical axis and close to said source of light so as to prevent the rays propagated. by that part of the source of light which lies below the optical axis from reaching the intensifying means. i

2. In a lam the combination of a source of light, re racting means arranged in front of said source of light, and a screen with a substantially horizontal upper edge, said screen being arranged close to and in front of said source of light and with its said edge substantially in or about the plane of the axis of the refracting means.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses;

WALTER CEGlIi MAN'IBY PET'llllGlLlJ.

Witnesses NORMAN S. BARLOW, NM. A. DAVIS. 

